Antibacterial acrylic resin composite coating and preparation process thereof

Abstract

The application provides an antibacterial acrylic resin composite coating and a preparation process thereof, and belongs to the technical field of coating preparation; the preparation process comprises the following steps: preparation of an antibacterial modifier; preparation of modified acrylic ester; preparation of modified zinc oxide; and preparation of a composite coating. The antibacterial effect of the modified acrylic ester is improved by modifying the acrylic ester with the antibacterial modifier, then HMDS and hydroxyl silicone oil are added to further improve the antibacterial effect of the composite coating.

Description

Technical Field

[0001] This invention relates to the field of coating preparation technology, specifically to an antibacterial acrylic resin composite coating and its preparation process. Background Technology

[0002] In the field of coating technology, acrylic resin coatings are widely used in building decoration, medical devices, food packaging and other fields due to their excellent weather resistance, gloss and color retention and film-forming properties. With the increasing awareness of public health and safety and the growing demand for long-lasting antibacterial protection, traditional acrylic resin coatings, due to their lack of antibacterial function, are no longer able to meet the requirements for use in scenarios where bacteria can easily grow, such as hospital walls, kitchens and bathrooms.

[0003] Existing antibacterial coatings mostly achieve their antibacterial effect by adding silver-based, copper-based, or quaternary ammonium salt-based organic antibacterial agents. However, metal ions are prone to migration and have poor compatibility with acrylic resin matrices, which can lead to uneven dispersion, reduce the physical and mechanical properties and antibacterial stability of the coating. Organic small molecule antibacterial agents, on the other hand, have the drawback of being easily lost, resulting in insufficient long-term antibacterial effect.

[0004] Therefore, we propose an antibacterial acrylic resin composite coating with both high antibacterial properties and good compatibility, and its preparation process. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an antibacterial acrylic resin composite coating and its preparation process.

[0006] An antibacterial acrylic resin composite coating, comprising the following components:

[0007] 60-70 parts by weight of modified acrylic emulsion, 0.1-0.3 parts by weight of defoamer, 0.2-0.5 parts by weight of leveling agent, 3-5 parts by weight of curing agent, 0.5-1 parts by weight of thickener and pre-dispersed modified zinc oxide slurry;

[0008] The pre-dispersed modified zinc oxide slurry comprises 15-20 parts by weight of modified zinc oxide, 1-2 parts by weight of dispersant and 10-13 parts by weight of deionized water;

[0009] The modified acrylate emulsion is obtained by copolymerization of an antibacterial modifier, azobisisobutyramidine hydrochloride, hexadecyltrimethylammonium chloride, fatty alcohol polyoxyethylene ether, benzyl methacrylate, n-butyl acrylate, hydroxyethyl acrylate, and glycidyl methacrylate.

[0010] The antibacterial modifier is obtained by reacting dimethylaminoethyl methacrylate, hexadecane bromide, and 2,6-di-tert-butyl-p-cresol.

[0011] The modified zinc oxide was obtained by synergistic modification of the coupling agent HMDS and hydroxyl silicone oil.

[0012] A preparation process for an antibacterial acrylic resin composite coating includes the following steps:

[0013] S1: Preparation of antibacterial modifier

[0014] 10-12 parts by weight of dimethylaminoethyl methacrylate, 18.8-19.3 parts by weight of hexadecane bromide and 0.01-0.02 parts by weight of 2,6-di-tert-butyl-p-cresol were added to 20-30 parts by weight of acetone. After the reaction, diethyl ether was added, followed by filtration, washing, and drying to obtain the antibacterial modifier.

[0015] S2: Preparation of modified acrylates

[0016] An antibacterial modifier, hexadecyltrimethylammonium chloride, and fatty alcohol polyoxyethylene ether were added to deionized water, followed by the addition of benzyl methacrylate, n-butyl acrylate, and azobisisobutyramidine hydrochloride solution to obtain a mixed solution. Benzyl methacrylate, n-butyl acrylate, hydroxyethyl acrylate, and glycidyl methacrylate were mixed to obtain a mixture. 2-3 parts by weight of the antibacterial modifier and hexadecyltrimethylammonium chloride, along with fatty alcohol polyoxyethylene ether, were added to deionized water to obtain a mixed liquid. The mixture and the mixed liquid were added dropwise to the mixed solution, and the reaction was carried out to prepare a modified acrylate emulsion.

[0017] S3: Preparation of Modified Zinc Oxide

[0018] First, adjust the pH of the 37wt% zinc oxide slurry to 9-10, then heat and add sodium silicate solution and coupling agent HMDS. After the reaction, add sodium aluminate solution to continue the reaction, and finally add hydroxyl silicone oil to prepare modified zinc oxide.

[0019] S4: Preparation of Composite Coatings

[0020] A composite coating is prepared by mixing and stirring 60-70 parts by weight of modified acrylic emulsion, 0.1-0.3 parts by weight of defoamer, 0.2-0.5 parts by weight of leveling agent, 3-5 parts by weight of curing agent, 0.5-1 parts by weight of thickener and pre-dispersed modified zinc oxide slurry.

[0021] Furthermore, the preparation of the antibacterial modifier in step S1 specifically includes the following steps:

[0022] 10-12 parts by weight of dimethylaminoethyl methacrylate, 18.8-19.3 parts by weight of hexadecane bromide, and 0.01-0.02 parts by weight of 2,6-di-tert-butyl-p-cresol were added to 20-30 parts by weight of acetone. The mixture was stirred and reacted with magnetic stirring at 300-500 r / min and 45-48℃ for 12-13 h. After the reaction was completed, the mixture was cooled to room temperature, and then 50-80 parts by weight of diethyl ether was added. The mixture was then filtered, washed, and dried to obtain the antibacterial modifier.

[0023] Furthermore, the preparation of the modified acrylate in step S2 specifically includes the following steps:

[0024] S2.1: Add 3-5 parts by weight of azobisisobutyramidine hydrochloride to 15-23 parts by weight of deionized water, and then stir to mix to obtain an azobisisobutyramidine hydrochloride solution;

[0025] S2.2: Add 10-12 parts by weight of antibacterial modifier, 5-8 parts by weight of hexadecyltrimethylammonium chloride and 3-5 parts by weight of fatty alcohol polyoxyethylene ether to 25-32 parts by weight of deionized water, mix by mechanical stirring, then add 10-12 parts by weight of benzyl methacrylate and 10-12 parts by weight of n-butyl acrylate, heat to 75-80℃, then add azobisisobutyramidine hydrochloride solution, stir and react for 1-2 hours to obtain a mixed solution;

[0026] S2.3: Mix 5-8 parts by weight of benzyl methacrylate, 5-8 parts by weight of n-butyl acrylate, 1-2 parts by weight of hydroxyethyl acrylate and 1-2 parts by weight of glycidyl methacrylate to obtain a mixture. Add 5-8 parts by weight of antibacterial modifier, 3-5 parts by weight of cetyltrimethylammonium chloride and 2-3 parts by weight of fatty alcohol polyoxyethylene ether to 15-20 parts by weight of deionized water to obtain a mixed solution.

[0027] S2.4: Add the mixture and the mixed liquid dropwise to the mixed solution at 75-80℃ for 2-3 hours. After the addition is complete, react for 2-3 hours, then cool to room temperature and filter to obtain the modified acrylate emulsion.

[0028] Furthermore, the preparation of modified zinc oxide in step S3 specifically includes the following steps:

[0029] Add sodium hydroxide to 15-20 parts by weight of 37wt% zinc oxide slurry, adjust the pH to 9-10, heat to 60-65℃, stir and mix for 20-30 minutes, then add 0.28-0.74 parts by weight of 10-12% sodium silicate solution and 0.03-0.15 parts by weight of coupling agent HMDS, then add sulfuric acid solution to adjust the pH to 9-10, keep the reaction at this temperature for 1-2 hours, then heat to 80-83℃, keep the reaction at this temperature for 2-3 hours, then cool to 60-63℃, add 0.17-0.37 parts by weight of 10-12% sodium aluminate solution, and simultaneously add sulfuric acid solution to adjust the pH to 9-10, react for 2-3 hours, then add 0.06-0.22 parts by weight of 5000 molecular weight hydroxyl silicone oil, maintain the pH to 9-10, react for 2-3 hours, then filter, wash, dry, and pulverize to obtain modified zinc oxide.

[0030] Furthermore, the preparation of the composite coating in step S4 specifically includes the following steps:

[0031] S4.1: Add 15-20 parts by weight of modified zinc oxide, 1-2 parts by weight of dispersant and 10-13 parts by weight of deionized water to a high-speed dispersion kettle and disperse at 800-1200 rpm for 20-30 min to form a pre-dispersed modified zinc oxide slurry.

[0032] S4.2: Add 60-70 parts by weight of modified acrylic emulsion to the reactor and stir at 300-500 rpm. Then slowly add pre-dispersed modified zinc oxide slurry, controlling the temperature at 25-30℃. Add 0.1-0.3 parts by weight of defoamer, 0.2-0.5 parts by weight of leveling agent, and 3-5 parts by weight of curing agent in sequence, stirring for 15-20 minutes. Finally, add 0.5-1 parts by weight of thickener, stir for 1-2 hours, sieve, and let stand for 24-25 hours to obtain the composite coating.

[0033] Furthermore, in step S3, the hydroxyl silicone oil is a hydroxyl silicone oil with a molecular weight of 5000.

[0034] Furthermore, the dispersant in step S4.1 is hydroxypropyl methylcellulose.

[0035] Further, in step S4.2, the curing agent is triglycidyl cyanurate, the leveling agent is leveling agent BYK354, the thickener is glyceryl stearate, and the defoamer is BYK-028.

[0036] Compared with the prior art, the present invention has at least the following beneficial effects:

[0037] 1. The antibacterial modifier of this invention is prepared by the quaternization reaction of dimethylaminoethyl methacrylate and hexadecane bromide. Its structure contains long-chain alkyl quaternary ammonium salt groups, whose positive charge can adsorb negatively charged bacterial cell membranes, disrupting the membrane structure and leading to bacterial death. The antibacterial modifier modifies the acrylate. In emulsion polymerization, the antibacterial modifier participates in copolymerization as a functional monomer, bonding to the acrylate backbone through copolymerization to form a stable and long-lasting antibacterial effect. The two additions of the antibacterial modifier ensure its uniform distribution in the polymer chain, avoiding insufficient local concentration or agglomeration, thus improving the overall antibacterial effect of the modified acrylate. Through covalent bonding with the resin, the antibacterial effect is more durable compared to physically mixed antibacterial agents, and it also avoids the problem of decreased antibacterial performance caused by the easy loss of small-molecule antibacterial agents.

[0038] 2. This invention controls particle size by simultaneously performing inorganic and organic modifications on zinc oxide. It also introduces organic substances, providing a foundation for subsequent organic modifications. HMDS, as a silane coupling agent, can adsorb onto the zinc oxide surface, reducing its surface energy and decreasing the tendency for particle aggregation. The introduced HMDS alters the surface polarity of zinc oxide, making it easier for zinc oxide to adsorb hydroxyl silicone oil. The hydroxyl silicone oil further coats the zinc oxide particles, creating a steric hindrance effect. The synergistic effect of these two modifications results in more uniform dispersion of zinc oxide in acrylic resin, avoiding performance inconsistencies caused by aggregation and improving the overall stability and consistency of the material.

[0039] 3. This invention incorporates modified zinc oxide into a composite coating. The modified zinc oxide is coated with coupling agent HMDS and silicate, increasing the number of surface active sites. This allows for a synergistic effect with the antibacterial modifier. The slow-release of Zn²⁺ from zinc oxide nanoparticles and the contact sterilization of organic antibacterial agents form a dual mechanism, effectively enhancing the antibacterial effect of the coating. Furthermore, after curing, the epoxy groups of the curing agent can react with the hydroxyl groups of the modified acrylate and also with the hydroxyl groups on the zinc oxide surface (hydroxyl silicone oil / silanol groups), forming a covalent bond connection of "polymer-curing agent-zinc oxide". This anchors the filler particles in the coating network. This process fixes the zinc oxide through chemical covalent bonds rather than physical adsorption, significantly improving the bonding force between the filler and the matrix, reducing agglomeration and detachment, and enhancing the longevity of the antibacterial effect. Attached Figure Description

[0040] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the invention and, together with the specification, further serve to explain the principles of the invention and enable those skilled in the art to practice and use the invention.

[0041] Figure 1 This is the structural reaction formula of the antibacterial modifier of the present invention.

[0042] Figure 2 The image shows the infrared spectrum of the antibacterial modifier of this invention.

[0043] Figure 3 This is a microscopic morphology diagram of the surface of the modified zinc oxide of the present invention. Detailed Implementation

[0044] The antibacterial acrylic resin composite coating and its preparation process provided by the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should also be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0045] Example 1

[0046] A preparation process for an antibacterial acrylic resin composite coating includes the following steps:

[0047] S1: Preparation of antibacterial modifier

[0048] 10 parts by weight of dimethylaminoethyl methacrylate, 18.8 parts by weight of hexadecane bromide and 0.01 parts by weight of 2,6-di-tert-butyl-p-cresol were added to 20 parts by weight of acetone and stirred at 300 r / min and 45 °C for 12 h under magnetic stirring. After the reaction was completed, the mixture was cooled to room temperature, and then 50 parts by weight of diethyl ether were added. The mixture was then filtered, washed and dried to obtain the antibacterial modifier.

[0049] S2: Preparation of modified acrylates

[0050] S2.1: Add 3 parts by weight of azobisisobutyramidine hydrochloride to 15 parts by weight of deionized water, and then stir to mix to obtain an azobisisobutyramidine hydrochloride solution;

[0051] S2.2: Add 10 parts by weight of antibacterial modifier, 5 parts by weight of hexadecyltrimethylammonium chloride and 3 parts by weight of fatty alcohol polyoxyethylene ether to 25 parts by weight of deionized water, mix by mechanical stirring, then add 10 parts by weight of benzyl methacrylate and 10 parts by weight of n-butyl acrylate, heat to 75°C, then add azobisisobutyramidine hydrochloride solution, stir and react for 1 hour to obtain a mixed solution;

[0052] S2.3: Mix 5 parts by weight of benzyl methacrylate, 5 parts by weight of n-butyl acrylate, 1 part by weight of hydroxyethyl acrylate and 1 part by weight of glycidyl methacrylate to obtain a mixture. Add 5 parts by weight of antibacterial modifier, 3 parts by weight of hexadecyltrimethylammonium chloride and 2 parts by weight of fatty alcohol polyoxyethylene ether to 15 parts by weight of deionized water to obtain a mixed solution.

[0053] S2.4: The mixture and the mixed liquid were added dropwise to the mixed solution at 75°C for 2 hours. After the addition was completed, the reaction was carried out for 2 hours. Then the mixture was cooled to room temperature and filtered to obtain the modified acrylate emulsion.

[0054] S3: Preparation of Modified Zinc Oxide

[0055] Sodium hydroxide was added to 20 parts by weight of 37 wt% zinc oxide slurry to adjust the pH to 9. The temperature was raised to 60°C and stirred for 20 min. Then, 0.28 parts by weight of 10% sodium silicate solution and 0.03 parts by weight of coupling agent HMDS were added. Then, sulfuric acid solution was added to adjust the pH to 9 and the reaction was maintained at -2 h. Then, the temperature was raised to 80°C and the reaction was maintained at 80°C for 2 h. Then, the temperature was lowered to 60°C and 0.17 parts by weight of 10% sodium aluminate solution was added. At the same time, sulfuric acid solution was added to adjust the pH to 9 and the reaction was maintained for 2 h. Then, 0.06 parts by weight of hydroxyl silicone oil with a molecular weight of 5000 was added and the pH was maintained at 9. The reaction was maintained for 2 h. Then, the mixture was filtered, washed, dried and pulverized to obtain modified zinc oxide.

[0056] S4: Preparation of Composite Coatings

[0057] S4.1: Add 15 parts by weight of modified zinc oxide, 1 part by weight of hydroxypropyl methylcellulose and 10 parts by weight of deionized water to a high-speed dispersion vessel and disperse at 800 rpm for 20 min to form a pre-dispersed modified zinc oxide slurry.

[0058] S4.2: Add 60 parts by weight of modified acrylic emulsion to the reactor and stir at 300 rpm. Then slowly add pre-dispersed modified zinc oxide slurry, control the temperature at 25℃, and add 0.1 parts by weight of defoamer BYK-028, 0.2 parts by weight of leveling agent BYK354, and 3 parts by weight of triglycidyl cyanurate in sequence. Stir for 15 min, and finally add 0.5 parts by weight of glyceryl stearate. Stir for 1 h, sieve, and let stand for 24 h to obtain the composite coating.

[0059] Example 2

[0060] A preparation process for an antibacterial acrylic resin composite coating includes the following steps:

[0061] S1: Preparation of antibacterial modifier

[0062] 10 parts by weight of dimethylaminoethyl methacrylate, 18.8 parts by weight of hexadecane bromide and 0.01 parts by weight of 2,6-di-tert-butyl-p-cresol were added to 20 parts by weight of acetone and stirred at 500 r / min and 48 °C for 13 h under magnetic stirring. After the reaction was completed, the mixture was cooled to room temperature, and then 50 parts by weight of diethyl ether were added. The mixture was then filtered, washed and dried to obtain the antibacterial modifier.

[0063] S2: Preparation of modified acrylates

[0064] S2.1: Add 3 parts by weight of azobisisobutyramidine hydrochloride to 15 parts by weight of deionized water, and then stir to mix to obtain an azobisisobutyramidine hydrochloride solution;

[0065] S2.2: Add 10 parts by weight of antibacterial modifier, 5 parts by weight of hexadecyltrimethylammonium chloride and 3 parts by weight of fatty alcohol polyoxyethylene ether to 25 parts by weight of deionized water, mix by mechanical stirring, then add 10 parts by weight of benzyl methacrylate and 10 parts by weight of n-butyl acrylate, heat to 80°C, then add azobisisobutyramidine hydrochloride solution, stir and react for 2 hours to obtain a mixed solution;

[0066] S2.3: Mix 5 parts by weight of benzyl methacrylate, 5 parts by weight of n-butyl acrylate, 1 part by weight of hydroxyethyl acrylate and 1 part by weight of glycidyl methacrylate to obtain a mixture. Add 5 parts by weight of antibacterial modifier, 3 parts by weight of hexadecyltrimethylammonium chloride and 2 parts by weight of fatty alcohol polyoxyethylene ether to 15 parts by weight of deionized water to obtain a mixed solution.

[0067] S2.4: The mixture and the mixed liquid are added dropwise to the mixed solution at 80°C for 3 hours. After the addition is complete, the reaction is carried out for 3 hours. Then the mixture is cooled to room temperature and filtered to obtain the modified acrylate emulsion.

[0068] S3: Preparation of Modified Zinc Oxide

[0069] Sodium hydroxide was added to 15 parts by weight of 37 wt% zinc oxide slurry to adjust the pH to 9. The temperature was raised to 65°C and stirred for 30 min. Then, 0.28 parts by weight of 10% sodium silicate solution and 0.03 parts by weight of coupling agent HMDS were added. Then, sulfuric acid solution was added to adjust the pH to 9 and the reaction was maintained at this temperature for 2 h. Then, the temperature was raised to 83°C and the reaction was maintained at this temperature for 3 h. Then, the temperature was lowered to 63°C and 0.17 parts by weight of 10% sodium aluminate solution was added. At the same time, sulfuric acid solution was added to adjust the pH to 9 and the reaction was maintained for 3 h. Then, 0.06 parts by weight of hydroxyl silicone oil with a molecular weight of 5000 was added and the pH was maintained at 9. The reaction was maintained for 3 h. Then, the mixture was filtered, washed, dried and pulverized to obtain modified zinc oxide.

[0070] S4: Preparation of Composite Coatings

[0071] S4.1: Add 15 parts by weight of modified zinc oxide, 1 part by weight of hydroxypropyl methylcellulose and 10 parts by weight of deionized water to a high-speed dispersion vessel and disperse at 1200 rpm for 30 min to form a pre-dispersed modified zinc oxide slurry.

[0072] S4.2: Add 60 parts by weight of modified acrylic emulsion to the reactor and stir at 500 rpm. Then slowly add pre-dispersed modified zinc oxide slurry, control the temperature at 30℃, and add 0.1 parts by weight of defoamer BYK-028, 0.2 parts by weight of leveling agent BYK354, and 3 parts by weight of triglycidyl cyanurate in sequence. Stir for 20 min, and finally add 0.5 parts by weight of glyceryl stearate. Stir for 2 h, sieve, and let stand for 25 h to obtain the composite coating.

[0073] Example 3

[0074] A preparation process for an antibacterial acrylic resin composite coating includes the following steps:

[0075] S1: Preparation of antibacterial modifier

[0076] 12 parts by weight of dimethylaminoethyl methacrylate, 19.3 parts by weight of hexadecane bromide and 0.02 parts by weight of 2,6-di-tert-butyl-p-cresol were added to 30 parts by weight of acetone and stirred at 300 r / min and 45 °C for 12 h under magnetic stirring. After the reaction was completed, the mixture was cooled to room temperature, and then 80 parts by weight of diethyl ether was added. The mixture was then filtered, washed and dried to obtain the antibacterial modifier.

[0077] S2: Preparation of modified acrylates

[0078] S2.1: Add 5 parts by weight of azobisisobutyramidine hydrochloride to 23 parts by weight of deionized water, and then stir to mix to obtain an azobisisobutyramidine hydrochloride solution;

[0079] S2.2: Add 12 parts by weight of antibacterial modifier, 8 parts by weight of hexadecyltrimethylammonium chloride and 5 parts by weight of fatty alcohol polyoxyethylene ether to 32 parts by weight of deionized water, mix by mechanical stirring, then add 12 parts by weight of benzyl methacrylate and 12 parts by weight of n-butyl acrylate, heat to 75°C, then add azobisisobutyramidine hydrochloride solution, stir and react for 1 hour to obtain a mixed solution;

[0080] S2.3: Mix 8 parts by weight of benzyl methacrylate, 8 parts by weight of n-butyl acrylate, 2 parts by weight of hydroxyethyl acrylate and 2 parts by weight of glycidyl methacrylate to obtain a mixture. Add 8 parts by weight of antibacterial modifier, 5 parts by weight of hexadecyltrimethylammonium chloride and 3 parts by weight of fatty alcohol polyoxyethylene ether to 20 parts by weight of deionized water to obtain a mixed solution.

[0081] S2.4: The mixture and the mixed liquid were added dropwise to the mixed solution at 75°C for 2 hours. After the addition was completed, the reaction was carried out for 2 hours. Then the mixture was cooled to room temperature and filtered to obtain the modified acrylate emulsion.

[0082] S3: Preparation of Modified Zinc Oxide

[0083] Sodium hydroxide was added to 20 parts by weight of 37 wt% zinc oxide slurry to adjust the pH to 10. The temperature was raised to 60℃ and stirred for 20 min. Then, 0.74 parts by weight of 12% sodium silicate solution and 0.15 parts by weight of coupling agent HMDS were added. Then, sulfuric acid solution was added to adjust the pH to 10 and the reaction was maintained at this temperature for 1 h. Then, the temperature was raised to 80℃ and the reaction was maintained at this temperature for 2 h. Then, the temperature was lowered to 60℃ and 0.37 parts by weight of 12% sodium aluminate solution was added. At the same time, sulfuric acid solution was added to adjust the pH to 10 and the reaction was maintained for 2 h. Then, 0.22 parts by weight of hydroxyl silicone oil with a molecular weight of 5000 was added and the pH was maintained at 10. The reaction was maintained for 2 h. Then, the mixture was filtered, washed, dried and pulverized to obtain modified zinc oxide.

[0084] S4: Preparation of Composite Coatings

[0085] S4.1: Add 20 parts by weight of modified zinc oxide, 2 parts by weight of hydroxypropyl methylcellulose and 13 parts by weight of deionized water to a high-speed dispersion vessel and disperse at 800 rpm for 20 min to form a pre-dispersed modified zinc oxide slurry.

[0086] S4.2: Add 70 parts by weight of modified acrylic emulsion to the reactor and stir at 300 rpm. Then slowly add pre-dispersed modified zinc oxide slurry, control the temperature at 25℃, and add 0.3 parts by weight of defoamer BYK-028, 0.5 parts by weight of leveling agent BYK354, and 5 parts by weight of triglycidyl cyanurate in sequence. Stir for 15 min, and finally add 1 part by weight of glyceryl stearate. Stir for 1 h, sieve, and let stand for 24 h to obtain the composite coating.

[0087] Comparative Example 1

[0088] Compared with Example 1, Comparative Example 1 differs in that the antibacterial modifier in steps S1, S2.2 and S2.3 is removed, while the remaining steps remain unchanged to prepare the composite coating, and it is referred to as Comparative Example 1.

[0089] Comparative Example 2

[0090] Compared with Example 1, Comparative Example 2 differs in that step S3 is removed, and the modified zinc oxide in step S4.1 is replaced with an equal mass of zinc oxide, while the remaining steps remain unchanged to prepare the composite coating. This is referred to as Comparative Example 2.

[0091] Comparative Example 3

[0092] Compared with Example 1, Comparative Example 3 differs in that the hydroxyl silicone oil in step S3 is removed, while the remaining steps remain unchanged to prepare the composite coating, and it is referred to as Comparative Example 3.

[0093] Comparative Example 4

[0094] Compared with Example 1, Comparative Example 4 differs in that the coupling agent HMDS in step S3 is removed in Comparative Example 4, while the remaining steps remain unchanged to prepare the composite coating, and is referred to as Comparative Example 4.

[0095] Comparative Example 5

[0096] Compared with Example 1, Comparative Example 5 differs in that the antibacterial modifier in steps S2.2 and S2.3 is removed, and the antibacterial modifier is added to S4.2 in equal parts by weight as an antibacterial agent, while the remaining steps remain unchanged to prepare the composite coating, which is referred to as Comparative Example 5.

[0097] The composite coatings obtained in Examples 1-3 and Comparative Examples 1-5 were sprayed onto standard test boards that had been pretreated according to the "GB / T9271-2008 Standard Test Boards for Paints and Varnishes" and cured at 150°C for 30 minutes to obtain test samples. Antibacterial tests for Escherichia coli and Staphylococcus aureus were performed on the test samples of Examples 1-3 and Comparative Examples 1-5. The test results are shown in Table 1.

[0098] Table 1. Results of antibacterial rate determination in Examples 1-3 and Comparative Examples 1-4

[0099]

[0100] As can be seen from the data in Table 1, the modification of acrylate by antibacterial modifier can effectively improve the antibacterial effect of coating. Furthermore, the synergistic modification of zinc oxide by HMDS and hydroxyl silicone oil can produce a synergistic effect with the antibacterial modifier, thereby improving the antibacterial effect.

[0101] The test samples of Examples 1-3 and Comparative Examples 2-5 were placed outdoors for 30 days and then tested again for antibacterial rates against Escherichia coli and Staphylococcus aureus. The test results are shown in Table 2.

[0102] Table 1. Results of antibacterial rate determination in Examples 1-3 and Comparative Examples 1-4

[0103]

[0104] As can be seen from the data in Comparative Example 5 in Table 2, compared with physically mixed antibacterial agents, the antibacterial modifier, as a functional monomer, has a longer-lasting antibacterial effect after copolymerization. As can be seen from Comparative Examples 2-4, the addition of encapsulated modified zinc oxide can significantly improve the antibacterial durability.

[0105] Figures 1-2 It can be seen that the antibacterial modifier was successfully synthesized. Figure 3 The modified zinc oxide exhibits a modified coating structure and good dispersibility.

[0106] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. An antibacterial acrylic resin composite coating characterized by, The composite coating comprises the following components: 60-70 parts by weight of modified acrylate emulsion, 0.1-0.3 parts by weight of defoaming agent, 0.2-0.5 parts by weight of leveling agent, 3-5 parts by weight of curing agent, 0.5-1 parts by weight of thickening agent and pre-dispersed modified zinc oxide slurry; The pre-dispersed modified zinc oxide slurry comprises 15-20 parts by weight of modified zinc oxide, 1-2 parts by weight of dispersant and 10-13 parts by weight of deionized water; The curing agent is cyanuric acid triglycidyl ester; The preparation method of the modified acrylate emulsion is as follows: 10-12 parts by weight of antibacterial modifier, 5-8 parts by weight of cetyltrimethylammonium chloride and 3-5 parts by weight of fatty alcohol polyoxyethylene ether are added to 25-32 parts by weight of deionized water, and then 10-12 parts by weight of benzyl methacrylate, 10-12 parts by weight of n-butyl acrylate and azobisdimethylamidino hydrochloride solution are added to obtain a mixed solution; 5-8 parts by weight of benzyl methacrylate, 5-8 parts by weight of n-butyl acrylate, 1-2 parts by weight of hydroxyethyl acrylate and 1-2 parts by weight of glycidyl methacrylate are mixed to obtain a mixture; 5-8 parts by weight of antibacterial modifier, 3-5 parts by weight of cetyltrimethylammonium chloride and 2-3 parts by weight of fatty alcohol polyoxyethylene ether are added to 15-20 parts by weight of deionized water to obtain a mixed solution; the mixture and the mixed solution are added dropwise to the mixed solution, and then reacted to prepare the modified acrylate emulsion; The antibacterial modifier is obtained by reacting 10-12 parts by weight of dimethylaminoethyl methacrylate, 18.8-19.3 parts by weight of bromohexadecane and 0.01-0.02 parts by weight of 2,6-di-tert-butyl-p-cresol; The preparation method of the modified zinc oxide is as follows: First, the pH of 15-20 parts by weight of 37wt% zinc oxide slurry is adjusted to 9-10, and then 0.28-0.74 parts by weight of 10-12% sodium silicate solution, 0.03-0.15 parts by weight of coupling agent HMDS are added, and after reaction, 0.17-0.37 parts by weight of 10-12% sodium metaaluminate solution is added for further reaction, and finally 0.06-0.22 parts by weight of hydroxyl silicone oil is added for reaction to prepare the modified zinc oxide.

2. The process for preparing an antibacterial acrylic resin composite coating according to claim 1, characterized in that, The method comprises the following steps: S1: Preparation of antibacterial modifier 10-12 parts by weight of dimethylaminoethyl methacrylate, 18.8-19.3 parts by weight of bromohexadecane and 0.01-0.02 parts by weight of 2,6-di-tert-butyl-p-cresol are added to 20-30 parts by weight of acetone, and after reaction, ether is added, and then filtered, washed and dried to obtain the antibacterial modifier; S2: Preparation of modified acrylate emulsion The 10-12 parts by weight of antibacterial modifier, 5-8 parts by weight of cetyl trimethyl ammonium chloride and 3-5 parts by weight of fatty alcohol polyoxyethylene ether are added into 25-32 parts by weight of deionized water, then 10-12 parts by weight of benzyl methacrylate, 10-12 parts by weight of n-butyl acrylate and azobisdimethylaminoformate hydrochloride solution are added to obtain a mixed solution; 5-8 parts by weight of benzyl methacrylate, 5-8 parts by weight of n-butyl acrylate, 1-2 parts by weight of hydroxyethyl acrylate and 1-2 parts by weight of glycidyl methacrylate are mixed to obtain a mixture; 5-8 parts by weight of antibacterial modifier, 3-5 parts by weight of cetyl trimethyl ammonium chloride and 2-3 parts by weight of fatty alcohol polyoxyethylene ether are added into 15-20 parts by weight of deionized water to obtain a mixed solution; the mixture and the mixed solution are added dropwise into the mixed solution, and then reacted to prepare a modified acrylate emulsion; S3: Preparation of modified zinc oxide First, the pH of 15-20 parts by weight of 37wt% zinc oxide slurry is adjusted to 9-10, then 0.28-0.74 parts by weight of 10-12% sodium silicate solution, 0.03-0.15 parts by weight of coupling agent HMDS are added under heating, after reaction, 0.17-0.37 parts by weight of 10-12% sodium metaaluminate solution is added for further reaction, and finally 0.06-0.22 parts by weight of hydroxyl silicone oil is added for reaction to prepare modified zinc oxide; S4: Preparation of composite coating The 60-70 parts by weight of modified acrylate emulsion, 0.1-0.3 parts by weight of defoaming agent, 0.2-0.5 parts by weight of leveling agent, 3-5 parts by weight of curing agent, 0.5-1 parts by weight of thickening agent and pre-dispersed modified zinc oxide slurry are mixed and stirred to prepare a composite coating.

3. The process for preparing an antibacterial acrylic resin composite coating according to claim 2, characterized in that, Step S1: Preparation of antibacterial modifier, specifically including the following steps: 10-12 parts by weight of dimethylaminoethyl methacrylate, 18.8-19.3 parts by weight of bromohexadecane and 0.01-0.02 parts by weight of 2,6-di-tert-butyl-p-cresol are added into 20-30 parts by weight of acetone, and stirred under magnetic stirring at 300-500 r / min and 45-48°C for 12-13 h. After the reaction is completed, the reaction solution is cooled to room temperature, then 50-80 parts by weight of diethyl ether is added, and then filtered, washed and dried to obtain the antibacterial modifier.

4. The process for preparing an antibacterial acrylic resin composite coating material according to claim 2, characterized in that, Step S2: Preparation of modified acrylate emulsion, specifically including the following steps: S2.1: 3-5 parts by weight of azobisdimethylaminoformate hydrochloride is added into 15-23 parts by weight of deionized water, and then stirred and mixed to obtain an azobisdimethylaminoformate hydrochloride solution; S2.2: 10-12 parts by weight of antibacterial modifier, 5-8 parts by weight of cetyl trimethyl ammonium chloride and 3-5 parts by weight of fatty alcohol polyoxyethylene ether are added into 25-32 parts by weight of deionized water, and then stirred and mixed, 10-12 parts by weight of benzyl methacrylate and 10-12 parts by weight of n-butyl acrylate are added, and then heated to 75-80°C, and then the azobisdimethylaminoformate hydrochloride solution is added, and then stirred and reacted for 1-2 h to obtain a mixed solution; S2.3: 5-8 parts by weight of benzyl methacrylate, 5-8 parts by weight of n-butyl acrylate, 1-2 parts by weight of hydroxyethyl acrylate and 1-2 parts by weight of glycidyl methacrylate are mixed to obtain a mixture, 5-8 parts by weight of an antibacterial modifier, 3-5 parts by weight of cetyl trimethyl ammonium chloride and 2-3 parts by weight of fatty alcohol polyoxyethylene ether are added to 15-20 parts by weight of deionized water to obtain a mixed solution; S2.4: the mixture and the mixed solution are added dropwise into the mixed solution at 75-80℃, the dropwise adding time is 2-3h, after the dropwise adding is completed, reaction is carried out for 2-3h, then cooled to room temperature, filtered to obtain a modified acrylate emulsion.

5. The process for preparing an antibacterial acrylic resin composite coating material according to claim 2, characterized in that, Step S3 for preparing modified zinc oxide, specifically comprising the following steps: 0.28-0.74 parts by weight of a 10-12% sodium silicate solution, 0.03-0.15 parts by weight of coupling agent HMDS are added, then a sulfuric acid solution is added to adjust the pH to 9-10, and the reaction is carried out for 1-2h, then the temperature is increased to 80-83℃, and the reaction is carried out for 2-3h, then the temperature is decreased to 60-63℃, 0.17-0.37 parts by weight of a 10-12% sodium metaaluminate solution is added, a sulfuric acid solution is added to adjust the pH to 9-10, and the reaction is carried out for 2-3h, then 0.06-0.22 parts by weight of a hydroxyl silicone oil with a molecular weight of 5000 is added, the pH is maintained at 9-10, and the reaction is carried out for 2-3h, then filtration is carried out, washed, dried, and crushed to obtain the modified zinc oxide.

6. The process for preparing an antibacterial acrylic resin composite coating material according to claim 2, characterized in that, Step S4 for preparing a composite coating, specifically comprising the following steps: S4.1: 15-20 parts by weight of the modified zinc oxide, 1-2 parts by weight of a dispersant and 10-13 parts by weight of deionized water are added into a high-speed dispersion kettle, and dispersed at a speed of 800-1200rpm for 20-30min to form a pre-dispersed modified zinc oxide slurry; S4.2: 60-70 parts by weight of the modified acrylate emulsion is added into a reaction kettle, the stirring speed is 300-500rpm, then the pre-dispersed modified zinc oxide slurry is slowly added, the temperature is controlled at 25-30℃, 0.1-0.3 parts by weight of a defoaming agent, 0.2-0.5 parts by weight of a leveling agent, 3-5 parts by weight of a curing agent are sequentially added, stirred for 15-20min, finally 0.5-1 parts by weight of a thickening agent is added, stirred for 1-2h, sieved, and left to stand for 24-25h to obtain the composite coating.

7. The process for preparing an antibacterial acrylic resin composite coating material according to claim 6, characterized by, The dispersant in step S4.1 is hydroxypropyl methyl cellulose.

8. The process for preparing an antibacterial acrylic resin composite coating material according to claim 6, characterized by, The leveling agent in step S4.2 is leveling agent BYK354, the thickening agent is glyceryl stearate, and the defoaming agent is BYK-028.

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